The human role in changing fluvial systems: Retrospect, inventory … · The human role in changing...

2006) 152–171www.elsevier.com/locate/geomorph

Geomorphology 79 (

The human role in changing fluvial systems:Retrospect, inventory and prospect

L. Allan James a,⁎, W. Andrew Marcus b,1

a Department of Geography, University of South Carolina, Columbia, SC 29208, United Statesb Department of Geography, University of Oregon, Eugene, OR 97403-1251, United States

Received 23 August 2005; received in revised form 15 June 2006; accepted 15 June 2006Available online 17 August 2006

Abstract

Historical and modern scientific contexts are provided for the 2006 Binghamton Geomorphology Symposium on theHuman Rolein Changing Fluvial Systems. The 2006 symposium provides a synthesis of research concerned with human impacts on fluvialsystems — including hydrologic and geomorphic changes to watersheds — while also commemorating the 50th anniversary of the1955Man's Role in Changing the Face of the Earth Symposium [Thomas, Jr., W. L. (Ed.), 1956a.Man's Role in Changing the Face ofthe Earth. Univ. Chicago Press, Chicago. 1193 pp]. This paper examines the 1955 symposium from the perspective of human impactson rivers, reviews current inquiry on anthropogenic interactions in fluvial systems, and anticipates future directions in this field.

Although the 1955 symposium did not have an explicit geomorphic focus, it set the stage for many subsequent anthropogeomorphicstudies. The 1955 conference provided guidance to geomorphologists by recommending and practicing interdisciplinary scholarship,through the use of diverse methodologies applied at extensive temporal and geographical scales, and through its insistence on anintegrated understanding of human interactions with nature. Since 1956, research on human impacts to fluvial systems has beeninfluenced by fundamental changes in why the research is done, what is studied, how river studies are conducted, and who does theresearch. Rationales for river research are now driven to a greater degree by institutional needs, environmental regulations, and aquaticrestoration. New techniques include a host of dating, spatial imaging, and ground measurement methods that can be coupled withanalytical functions and digital models. These new methods have led to a greater understanding of channel change, variations acrossmultiple temporal and spatial scales, and integrated watershed perspectives; all changes that are reflected by the papers in this volume.These new methods also bring a set of technical demands for the training of geomorphologists. The 2006 Binghamton GeomorphologySymposium complements the 1956 symposium by providing a more specific and updated view of river systems coupled with humaninteractions. The symposium focuses on linkages between human land use, structures, and channel modification with geomorphology,hydrology, and ecology. The emergence of sustainability as a central policy guideline in environmental management should generategreater interest in geomorphic perspectives, especially as they pertain to human activities. The lack of theories of anthropogeomorphicchange, however, presents a challenge for the next generation of geomorphologists in this rapidly growing subfield.© 2006 Elsevier B.V. All rights reserved.

Keywords: Human impacts; Fluvial geomorphology; Watersheds; Hydrology; Rivers

⁎ Corresponding author. Tel.: +1 803 777 6117; fax: +1 803 777 4972.E-mail addresses: [email protected] (L.A. James),

[email protected] (W.A. Marcus).1 Tel.: +1 541 346 5709.

0169-555X/$ - see front matter © 2006 Elsevier B.V. All rights reserved.doi:10.1016/j.geomorph.2006.06.017

1. Introduction

The 2006 Binghamton Geomorphology Symposiumhas two purposes. The first purpose is to provide a synthesisof research on human impacts on river morphology. The

mailto:[email protected]

mailto:[email protected]

http://dx.doi.org/10.1016/j.geomorph.2006.06.017

Fig. 1. George P. Marsh, photographed by Mathew B. Brady between1855 and 1865. Brady-Handy Collection (Library of Congress). [callnumber: BH8201-4981; reproduction number: LC-BH8201-4981DLC (b&w film copy neg.)].

153L.A. James, W.A. Marcus / Geomorphology 79 (2006) 152–171

majority of papers in this volume, therefore, focus onspecific causes of change in rivers or look at cumulativehuman impacts on rivers at regional to global scales. Asecond purpose of the symposium is to commemorate the50th anniversary of the 1955Man's Role in Changing theFace of the Earth conference and its 1956 proceedingsvolume (Thomas, 1956a), henceforth referred to collec-tively as Changing the Earth. Through the examination ofhuman impacts on fluvial geomorphology, the researchpapers in this volume carry on the tradition of the 1955symposium and honor the work of our scholarly predeces-sors. In addition, several articles explicitly identify some ofthe links between the 1955 symposium and this 2006Binghamton conference.

This paper provides historical and conceptual contextfor the 1955 and 2006 symposiums by summarizingsome of the major changes since 1955 and outlining thechallenges and opportunities for research concerned withhuman impacts on fluvial systems as exemplified bypapers in this volume. The purpose is not to provide acomprehensive historical review of human impactstudies in fluvial geomorphology. This paper does notaddress the full scope of human impact studies in fluvialsystems, especially as they have occurred outside Europeand English-speaking countries. Nor does it attempt tosurvey the vast literature on human-nature relations andhuman impact studies. Rather, the purpose of this paperis threefold: (A) to set the stage for later articles in thisvolume with a retrospective review of the 1956 Chan-ging the Earth proceedings and some of its links to the2006 Binghamton Symposium, (B) to review changes inthe research process since 1956 with a focus on why,what, and how human impacts are studied, and (C) toidentify prospective directions in this field. This pers-pective is intended to provide a broad context for manyof the key issues raised by papers in this volume.

2. Retrospect: The 1956 Changing the Earthproceedings

The 1956 proceedings, Changing the Earth (Thomas,1956a), presented many examples and explanations ofhuman-caused environmental changes, especially inEurope and North America. This novel synthesis ofpreviously disparate findings from many different fieldsand locations helpedmotivate and inform two generationsof scholars through its recognition of the long-termhistorical roots and the spatial extent of human impacts tothe face of Earth. As important as those proceedings were,however, they did not arise from a vacuum. Substantialwork on human impacts preceded theChanging the EarthSymposium. This review begins with a brief synopsis of

the origins of concern about anthropogenic change incolonial North America, although such concepts can betraced elsewhere to antiquity (Glacken, 1967).

2.1. Precursors to the Changing the Earth Symposium

Precursors to the Changing the Earth Symposium inNorth America can be traced to concerns aboutdestruction of natural resources seen in the writings andpaintings of 19th century artists, poets, and scholars suchas John James Audubon (1831–39), Susan FenimoreCooper (1850), Henry David Thoreau (1854), and S.H.Hammond (1857), to name a few of the prominent voices(James, in press). After the Civil War in the United States,concerns over global-scale anthropogenic changes weregreatly influenced by Man and Nature, George PerkinsMarsh's (1864) classic work that documented the breadthof human impacts on natural systems. As the son of aU.S. Congressional Representative and as a paleon-tologist, diplomat to Turkey and Italy, an architect of theWashington Monument, and scholar of languages, Marsh(Fig. 1) moved in high intellectual and political circles

154 L.A. James, W.A. Marcus / Geomorphology 79 (2006) 152–171

(Lowenthal, 1965). His stature increased the effectivenessand dissemination of his ideas, ensuring that Man andNature was widely read and acknowledged as animportant work in physical geography. Moreover,Marsh's thesis that humans were causing seriousdestruction that endangered nature as well as society,resonated with contemporary public sentiment. Marsh'sbook was the first to integrate the ideas that humans arepart of nature but also rely heavily on nature, that themagnitude of human impacts could exceed the ability ofnature to recover, and that nature was frail in the face ofhuman exploitation. Prior to Marsh, the common viewwas that Earth molded human nature and that globalresources were abundant. After Marsh, an alternativeawareness emerged that humans change a natural worldthat is composed of finite resources (Lowenthal, 1990).Marsh's work was critical in changing the perception ofnature froma fear of thewrath ofGod to a fear of thewrathof nature (Pisani, 1996). Man and Nature has beendescribed as “the fountainhead of the conservationmovement” (Mumford, 1931, in Lowenthal, 1965). Hiswritings on natural processes were widely influential ongeomorphologists of the late 19th century through thework of explorers such as Hayden, Newberry, Wheeler,and Powell (Vitek and Ritter, 1993).

An extensive review of early 20th century writing onhuman transformations is given in the original Chan-ging the Earth proceedings (Thomas, 1956b). A few keyindividuals and works, as noted by Thomas, deservespecial mention for works that have direct bearing ongeomorphic systems discussed in this volume. Forexample, the Russian, German, and French writings ofAlexander Ivanovich Woeikof of Saint Petersburg werewidely read in Europe. His writings focused on human-induced soil erosion and sedimentation through themodification of vegetation by grazing, fire, andurbanization (Woeikof, 1901). Neither Marsh norWoeikof addressed population growth as a cause ofchange or human impacts outside of the northern andwestern hemispheres. Nathaniel Southgate Shaler, aHarvard geology professor, took up Marsh's conserva-tion mantle but went further by identifying the linkbetween rapid population growth and resource depletionand damage to pristine natural systems (Shaler, 1905).As a geologist, Shaler was interested also in soil erosionand agricultural practices.

In the late 19th and early 20th centuries in the UnitedStates, rapid landscape development and degradation led toa greater recognition of the need for conservation.Strengthening of the conservation movement was charac-terized by scientific land-management policies broughtfrom Europe by Gifford Pinchot. These policies sought to

conserve resources andmaintain federal land ownership, incontrast to earlier policies aimed at distributing governmentlands to private owners (Hays, 1959). Continued popula-tion growth and resource consumption coupled withgrowing alienation of preservationists, however, limitedthe effectiveness of the conservation movement incurtailing erosive land use, river fragmentation, and otherlandscape alterations (Fox, 1985). The inability ofconservation policies to stop environmental degradationand the ability of humans to alter geomorphology atlandscapes scales was made clear by the 1930s Dust Bowldisaster, and the massive dam-building efforts initiatedunder Roosevelt's New Deal. The shocking potential forhumans to radically and almost instantaneously disruptenvironmental and geomorphic systems was suddenlydemonstrated by the 1945 Hiroshima nuclear bomb, andsustained by subsequent attempts of Project Plowshare toharness nuclear explosions for excavating mines, canals,aqueducts, roadways, and harbors during the 1940s and1950s (Kiersch, 1998; Neal, 1998). Post-World War IIpublic action and scholarly research on human impacts tothe Earth thus proceeded during a period of fundamentallychanged perceptions of the effectiveness of humans asagents of change.

2.2. The Changing the Earth Symposium and itsgeomorphic legacy

The combination of rapid environmental degrada-tion, increasing technical potential, and evolvingpolitical philosophies created a fertile ground for asymposium on human impacts to Earth. Yet, it still tookthe efforts of William L. Thomas, Jr., Assistant Directorof research at the Wenner–Gren Foundation, to bring theChanging the Earth conference to life. The active leadof Thomas and the Wenner–Gren Foundation, whichwas dedicated to the advancement of anthropology(Fejos, 1956, p. vii), encouraged many of the studies inthe proceedings to address the origins of human cultureand how cultural history relates to landscape changesover time periods spanning the Holocene. The Chan-ging the Earth Symposium, however, was not onlyabout anthropological findings. Thomas asked CarlSauer to chair the conference and help in its organiza-tion, and together they took a broadly geographicalapproach to its content (Thomas, 1956b). Participantscame from diverse origins and eclectic professionalbackgrounds; the perspectives they brought wereequally broad. While the Changing the Earth proceed-ings did not have an explicit geomorphic focus, theyprovided perspectives that remain relevant to humanimpact studies in geomorphology to this day.


2.2.1. Geomorphology in the Changing the Earthproceedings

Despite its breadth, the emphasis of the Changing theEarth Symposium on human alterations, and its extensivediscussion of geomorphically important variables such asclimate, land use, vegetation, mining, urbanization andagriculture, surprisingly little direct attention was paid tolandform change. Geomorphic issues continually emergedin various guises throughout the proceedings, but onlyrarely were they the primary focus. The term “geomor-phology” is only cited twice in the index for a 1193-pagetext; once when it is used by Carl Sauer (1956, p. 61) in alist of topics one must know to understand changes inhabitability, the other time byArthur Strahler (1956, p. 621)in explaining how his perspective differs from that of anengineer examining soil erosion and aggradation. “Geo-morphogeny” is used as a heading in a critical discussion ofDavisian geomorphology (Russell, 1956).

Early concepts of humans as geomorphic agents mayhave underestimated the geomorphic effectiveness ofcultural activities. By the 1920s, however, awareness wassufficient to generate a call from Seuss for the addition ofthe noösphere (bGreek noös=mind) to the realms ofEarth in addition to the lithosphere, hydrosphere,biosphere, and atmosphere (de Chardin, 1956; Fig. 2).By the year 2000, increasing realization of the geomor-phic effectiveness of humans was driving the emergence

Fig. 2. Pierre Teilhard de Chardin at the Princeton Symposium in 1956.Source: Wenner Gren Foundation. Printed with permission.

of a new human-impacts sub-field in geomorphology(e.g., Haff, 2001). It also led to calls for distinguishing themodern period — following the late 1700s — as a newgeologic epoch known as theAnthropocene, characterizedby distinct evidence of human activities preserved in thegeologic record (Crutzen and Stoermer, 2000; Crutzen,2002).

The limited attention in the Changing the Earthproceedings given to human impacts on river habitatswarrants attention because of the key role that riversplay in cultural activities. When rivers were discussed,most of the emphasis was on built structures, such ascanals and irrigation works (Klimm, 1956; Sears, 1956;Wittfogel, 1956), on water quantity (Thomas, 1956c), oron factors that affect water quality such as sedimentyield (Leopold, 1956) and human waste (Wolman,1956). The physical habitat and geomorphology ofrivers were generally ignored except for brief mention ofnatural factors such as river capture or changes inchannel course that alter river flows and humanhabitability (Huzayyin, 1956; Russell, 1956). Refer-ences to human-induced changes in river morphologyare mostly in relation to river mouths and deltas (Davis,1956; Klimm, 1956). Two papers directly addressedsurface runoff, sediment, and fluvial changes. Strahler(1956) focused on drainage density and upland rivervariables by introducing Horton's quantitative hydrol-ogy concepts in the context of human impacts. Leopold(1956) focused on the relation between sediment yieldand land use, although he could not resist talking aboutstream channels, making the prescient comment that:

…man's work directly on river channels has been andprobably will continue to be a far more importantdeterminant of future channel conditions than thenatural operation of river mechanics in response toman's changes on the watershed. It is probable thatlong before the effects of the latter can occur, riverconditions will have been so altered by dams that[dams] will be the primary factor in controlling river-channel characteristics (Leopold, 1956, p. 646).

The relative importance of watershed-wide land-useimpacts and dam impacts on channel morphology can bedebated, but Leopold's comment foreshadowed themodern research emphasis on effects of dams on rivers(e.g., Beyer, 2005; Graf, 2006-this volume; Poff et al.,2006-this volume).

Fluvial geomorphology was not completely missingfrom the Changing the Earth Symposium, but it was notan explicit focus of the articles. Many of the chaptersreferred to the effects of agriculture, forest clearing, ur-banization, fire, and other human activities on runoff and

Fig. 3. Four domains of fluvial geomorphic theory postulated byChurch (1996) as functions of time and space. The two lines depictapproximate rates of water flow (1 m s−1) and sediment transport (100m year−1). The five fields represent a scale dependency of theoreticalcausality or explanation that is important to considerations of humanagency in geomorphic processes. Adapted from Church (1996).


soil erosion. The emphasis was usually on the socioeco-nomic and cultural changes that led to these impacts,however, rather than on downstream implications of theimpacts. The emphasis on upland changes rather thanriparian impacts reflected a pervasive contemporary biasof the soil-conservation movement towards on-site issueswhile disregarding off-site effects. Soil conservationists inthe United States during the 1930s and 1940s providednumerous examples of soil stewardship, but few instancesof concern for downstream impacts (James, in press). Thismay have reflected a widespread lack of perception of thevalue of aquatic systems to public and environmentalhealth or of the pervasive nature of riparian and wetlanddestruction (see Happ, 1944 for an exception). Concernfor offsite losses began to build in the 1950s and was akeystone of the environmental movement in the 1960s.

The lack of geomorphology or concern for fluvialsystems in the Changing the Earth proceedings can beexplained, in part, by the tremendous breadth ofenvironmental impacts covered in the symposium.Few areas in the litany of topics addressed in Chan-ging the Earth are undeserving of coverage. To thecontrary, the list of relevant human impacts is so largethat river impacts are subsumed within the vast panoplyof human impacts.

If the Changing the Earth Symposium did notaddress geomorphology per se, however, why hold ageomorphology symposium that commemorates theChanging the Earth contributions? The answer is thatthe documentation and guidance provided by theChanging the Earth conference has been a majorimpetus to subsequent in-depth environmental scholar-ship — research that includes studies of human impactsin fluvial geomorphology, the focus of the 2006Binghamton Symposium. In particular, the Changingthe Earth proceedings provided an excellent prototypeof the broad-scale mixing of natural and societalperspectives needed to develop a compelling synthesisof anthropogenic changes to fluvial systems.

2.2.2. Broad scale approaches and the melding ofnature and culture

The Changing the Earth Symposium contributed tomodern thinking, in part, through its advocacy anddemonstration of certain approaches in studying humanimpacts—methodological perspectives that in some waysneeded to be rediscovered in geomorphology. Thesemethods employed broad scales of time and space. Bytaking the long view (the anthropological view) of humanhistory and impact, the conference foreshadowed modernhuman-impact approaches in geomorphology, wherehistorical process and contingency play key roles in

explaining landscape characteristics, and geomorphicexplanation requires more than static equations based onNewtonian physics. Ironically, at the very time of theconference, geomorphology was undergoing a sweepingchange in its methodologies by abandoning the historicalDavisian approaches in favor of more reductionistapproaches that quantified relations between process andform, and examined the role of humans by using these newphysical science-based approaches (Goudie, 1995, 2000).These quantitative process studies, however, tended tooperate at moderately small scales of time and space toavoid the data needs and non-linearities of longer-term,broader scales (Fig. 3).Moreover, even at local scales, thesequantitative studies of processes often sought to eliminateor control for the effects of human agency that couldobscure mechanistic process–response relationships.

The Changing the Earth Symposium also maintaineda broad spatial perspective and emphasized the land-scape scale. From a geomorphic viewpoint, the emphasison landscape scale is most notable in Strahler's (1956)article where he explicitly explains the rationale for thelandscape process approach, in part to counter the plot-specific work that process-based scientists with engi-neering backgrounds had emphasized. The Changingthe Earth volume also emphasized change through timein specific regions, landscapes, or ‘faces’ as they werelater referred (Turner et al., 1990). This landscape scaleof analysis now dominates much of the human impactwork in fluvial geomorphology and is being encouragedby integrated watershed approaches described later.


In its documentation of human impacts in manyregions of the Earth over several millennia, Changingthe Earth presaged the modern recognition that finding atruly “natural” fluvial system may be difficult (Graf,1996), and that humans and nature are inextricablyintertwined within the fluvial landscape. This, in turn,reinforced the contingent nature of geomorphology andhuman agency, where river systems in similar naturalenvironments can vary greatly between different culturallandscapes. Such systems cannot be completely modeledusing linear equations of force and resistance to simulatethe natural elements in isolation, but are best character-ized with an understanding of idiosyncrasies of culturaltraits and histories. Glacken (1956, p. 87) describes thismodern scientific challenge by emphasizing the impor-tance of considering humans as part of nature:

If human activities, however, are considered — ordefined — as interferences with this balance [ofnature], we assume the existence of a nature which isan abstraction, and we neglect the effects of prehistoricand historic cultures on the natural environment. Theseeffects are historical events, and, if not regarded assuch, the study of human cultures, with their mass ofcustoms and traditions, and the study of physicalenvironments will go their separate ways, and the gapbetween the two will be bridged with metaphors.

In a fluvial context, this means that the history of human-river interactions must be known to fully understandconsequences to rivers and to humans. Fifty years later, inthese proceedings, Gregory (2006-this volume) echoesthis same call to contemplate a “cultural geomorphology:”

It is therefore not possible to prescribe a universalapproach to managing rivers, but only one whichreflects the influence of the particular cultural overlay.Therefore it is now timely for geomorphologists toraise awareness of such cultural distinctions and toconsider these when constructing recommendations.

2.2.3. Scholarly purposeThe 1955 conference foreshadowed current trends in

geomorphology, such as historically contingentapproaches, the intertwining of culture and nature, andanalysis at landscape scales. Providing methodologicalexemplars was not the primary purpose of the proceed-ings, however, and Thomas (1956b, p. xxii) was veryclear in stating that the primary objective was publicationof a permanent record accessible to a large audience andavailable to future scholars. The conference succeeded inthis regard, providing expansive and, at times, over-whelming documentation of human transformation of

Earth. At a simple inventory level, the conference provid-ed the baseline documentation that was needed to justifymaking research on human impacts a major priority. Thescholarly influence of the symposium, however, wentbeyond simple inventory. Through its comprehensivedocumentation and explanation of the true breadth ofhuman impacts on Earth, Changing the Earth provided agathering point; that is, a unified vision of the many andvaried types of environmental degradation resulting frompopulation growth, accelerating rates of consumption ofresources, and the lack of societal awareness about theconsequences of cultural habits. These visions were frommany different perspectives and were integrated overbroad temporal and spatial scales. Although the volumehas been criticized for taking “a tad indifferent” tone thatdid not push the public to action (Wilson, 2005), thisopinion seems unduly harsh. The proceedings werewritten so that articles could be read by the educatedpublic, but the primary audience was clearly a scholarlyone. Its explicit goal was to generate an objective, newscientific synthesis. To criticize it for lacking the rhetoricaland emotional appeal of Rachel Carson's (1962) SilentSpring is to misconstrue its central purpose.

More than any particular article or new concept, thesense of scientific exploration within the proceedings ofChanging the Earth has influenced scholars over severalgenerations. Within academia the conference providedan enduring model for the multidisciplinary study ofenvironmental degradation. Global change research andthe current branch of geography often referred to as“Nature and Society” were encouraged and influencedby Changing the Earth (Kates et al., 1990; p.4). Just asearth science was moving more and more towardsspecialization with a narrowing focus of professionalexpertise in individual fields, Changing the Earthprovided a much-needed synthesis in the oppositedirection. By inviting experts from a great diversity offields, new interdisciplinary ties were forged and a newgeneration of scholars emerged in the 1960s and 1970swith new perspectives. The work of these scholars andthe students they trained ultimately led to this 2006Binghamton Geomorphology Symposium on TheHuman Role in Changing Fluvial Systems.

3. Changes in research since the Changing the EarthSymposium

Much has transpired in human impact studies in fluvialsystems since the scholarly environmental perspectives of1956. More is now known about the history, locations,sequence, and agents of change in fluvial systems.Technologies, methods, theoretical constructs, and the


social setting of human impact studies are remarkablydifferent than they were two generations ago. Rather thanattempting an encyclopedic review, an overview isprovided here of some major changes in geomorphicresearch since 1956, particularly as they relate to the 2006Binghamton proceedings (see Walker and Grabau (1993)for a more comprehensive summary of the historicalevolution of geomorphic research in the late 20thcentury). These changes are described in terms of whyscholars study human impacts in rivers, what is beingstudied over various time periods, how data have beencollected and analyzed, and who has carried out thestudies.

3.1. Why study human impacts on fluvial systems?

Many motivations for studying anthropogenicimpacts to fluvial systems are similar to the reasonsgiven in 1956 for studying broader environmentalimpacts. These include documentation, inventory, andexplanation of change, as well as a desire to amelioratethe destructive influences of humans on nature. Sincethat time, however, some new rationales have emergedand some existing ones have evolved and taken ongreater import. To a much greater degree than in 1956,rationales for studying human impacts on rivers are nowdriven by institutional needs, concerns over futureenvironmental change, and a growing desire to restorenatural functionality to streams.

3.1.1. Institutional needs and environmentalregulations

Discussion of regulation or policy-driven researchtopics is nearly absent from the 1956 proceedings,although Abel Wolman's (1956) paper addresses theneeds of water quality in this context. Other contemporaryfluvial research outside the 1956 proceedings was alsolargely devoid of applied environmental topics, with theexception of flood control, soil erosion, and water quality;topics that were mostly treated from the perspective ofprotecting human safety and economic well being. Since1956, however, establishment of a wide array ofenvironmental regulations and a growing awareness ofenvironmental change and degradation have motivatedsupport for a growing amount of environmental monitor-ing and research. Environmental legislation affectingrivers in the USA range from the National EnvironmentalPolicy Act and the Endangered Species Act to the CleanWater Act; similar laws exist in other developed nations.These laws have promoted environmental research andthe development of research protocols. They have im-proved understanding of hydrogeomorphic topics ranging

from the establishment of sediment quality standards(Marcus, 1989, 1991), to recommendations for develop-ing geomorphic indicators of stream health (Graf, 2001),to guidelines for stream restoration (Rosgen, 1996).

Because government agencies and funding institu-tions support much of the modern scholarship on rivers,much of the rationale for modern studies of impact inrivers is related to activities that agencies manage orattempt to influence. These activities are largely inresponse to accelerating pressures from development, agrowing awareness of health effects and environmentaldegradation, and environmental regulations intended topreserve, conserve, or restore natural systems. In theUnited States, institutional initiatives for watershed orriver studies take the form of requests for proposals(RFPs) from funding agencies, which typically focus onunderstanding the history and processes of change andpredicting future change under different developmentand mitigation scenarios. Motives for these studiesinclude development of viable strategies to protect andenhance water quality, public health, aquatic ecosystems,individual species, flood-conveyance systems, and waterresources. RFP-driven rationales may seek explanation,but are often more concerned with applications ofexisting knowledge to develop rational river policies,management tools, or engineering solutions to specificproblems. In this context, the reasons for studying riversoften take on a more pragmatic, applied perspective thanwas demonstrated in the 1956 proceedings.

Growing institutional concerns about global toregional change also provide greater incentives forresearch on environmental impacts than in the past. Anincreasing number of studies focus on how rivers haveresponded or are expected to respond to deforestation,agriculture, urbanization, or climate change. The rationalefor these studies is typically expressed in terms of trying tounderstand and predict future response of rivers in order tostabilize and maintain present river environments, or todevelop adaptive policies in response to those changes.

3.1.2. Aquatic restorationGrowing awareness of the magnitude of fluvial change

has led to an increasing emphasis on understanding waysin which altered fluvial systems can be restored.Recognition of the extreme changes that many fluvialsystems have undergone and the consequences of thesechanges — positive and negative — is a first step inensuring that policies are implemented based on informedcriteria. For example, stream ‘restoration’ has becomeemblematic to many river management programs and isbeing widely practiced (e.g., Brooks et al., 2006-thisvolume, provide Australian examples). The general


rationale for restoration projects and related research isreadily apparent from any inventory of advancingpopulation growth, resource depletion, environmentaldegradation, and esthetic disfigurement of natural sys-tems. The specific motivations behind “restoration”projects vary dramatically, however, with land ownership,funding agency, and cultural setting. The definition ofrestoration thus ranges from attempts to return streams to apre-disturbance state to stabilization projects with struc-tural armoring that may disrupt natural processes andreduce habitat diversity. A common definition ofrestoration requires that stream channels be returned to aprevious condition (NRC, 1992). This criterion calls forexplicit historical reconstructions of changes to the fluvialsystem, a practice that requires geomorphic expertise.

To restore a river on a sustainable basis often requiresthat the processes controlling channel adjustments beunderstood at a scale extending well upstream of aspecific stream reach and over multi-generational timeperiods. An understanding is needed, therefore, of thewater and sediment loads integrated over the watershed,which has led to a growth in integrated watershed as-sessment as a tool in river restoration. Integrated appro-aches, described later, require geomorphic expertise inriver processes and should include an assessment of thekey contemporary and historic physical, ecological, andsocial controls on river change. These needs call forgeomorphic studies to go beyond physical processes toexamine also social aspects of river systems such aseconomic pressures, land-use policies, and historicaldevelopment. Strong ties between ecologists andgeomorphologists are now emerging (e.g., Malanson,1993), as exemplified by the 1995 BinghamtonSymposium devoted to Geomorphology and Ecosys-tems (Hupp et al., 1995).

3.2. What is studied and when

As with all research disciplines, certain conventionaltopics in fluvial geomorphology have received closeattention while other potential areas of study have gonelargely unattended. TheChanging the Earth proceedingsemphasized change through time at specific regions andlandscapes, or ‘faces’ as they have been referred to. Asubsequent conference known as the Earth TransformedSymposium (Kates et al., 1990) placed additionalemphasis on fluxes of energy and mass, thus framingmany of the physical questions raised by the study ofanthropogenic changes in terms compatible with main-stream physical science. This section identifies someways in which the focus of research concerned withhuman impacts on fluvial systems has changed since the

1950s in response to research on channel changes, scalesof observation, integrated watershed analysis, andclimate change. This list is by no means comprehensivein terms of factors that have changed since 1956; rather,it highlights notable changes addressed by papers in thisvolume.

3.2.1. Channel changesChannel hydraulics and morphology were addressed

peripherally in Changing the Earth, and largely from adifferent perspective than that taken by contemporaryscholars — although some familiar refrains can beheard. For example, an awareness of human impacts onrivers clearly existed, but many of the implications ofthese changes were not brought out. Klimm (1956)notes, for instance, that the Grand Canal and otherprojects on the China plain are of such antiquity thatdistinguishing between canals and natural channelsystems is often impossible, but he does not describehow modified systems differ from natural ones. Incontrast, the Leopold (1956) comment noted in Section2.2.1 presaged the modern documentation of riverdisruption by dams and indicated an appreciation forthe implications of fragmentation. Most radical perhapswas Wittfogel's (1956) advocacy for a theory of hy-draulic civilizations, which postulated that civilizationsprings not from urbanization, but from the develop-ment and maintenance of irrigation agriculture. Thegeomorphic implication of Witfogelian theory is thatriver regulation is not simply a side effect of humanoccupation, but represents an inherent and prerequisitecondition of civilization.

The central role that channel hydraulics andmorphology now play in the studies of human impactson rivers is represented by the 2006 BinghamtonSymposium (this volume), which contains an overviewof the topic (Gregory, 2006-this volume) as well asarticles on impacts of channelization and leveeing(Simon and Rinaldi, 2006-this volume), dams (Graf,2006-this volume; Poff et al., this volume), agriculturalland clearance in the upper Midwest, USA (Knox, 2006-this volume), mining (Macklin et al., 2006-this volume),urbanization (Chin, 2006-this volume; Kang andMarston, 2006-this volume), and alterations of animalpopulations (Butler, this volume). This list does notinclude additional potential impacts such as logging,roads, gravel extraction, and a host of other types ofresource uses in and around rivers. The discussions ofthe morphologic changes of channels in most of thearticles in this volume reflect the central role thatchannel change has taken in modern studies of humanimpacts on rivers.


3.2.2. Scales of observations — time and spaceIdentifying scales of data and research focus is critical

to developing a proper interpretation of anthropogeo-morphic impacts. For example, broad landscape-scalechanges that have accumulated over a long period of theHolocene and recent local effects of urbanization are bothexhibited in the same riverscape. Allocating how muchvariability is driven by each impact is difficult at best andsometimes impossible, as is exemplified by the contro-versy over anthropogenic versus climatic drivers of arroyocutting in the southwestern USA (Cooke and Reeves,1976). Although time was explicitly addressed in the1950s human impacts literature, from a theoretical basisand from a practical methodological basis, considerabledifficulty was encountered in separating anthropogenicfrom natural causes and effects across multiple scales.

From a theoretical perspective, Schumm and Lichty's(1965) simple but widely influential paper provided a basisfor distinguishing between independent and dependentvariables and helped to structure many geomorphicarguments around concepts of space and time. McDowellet al. (1990) refined these arguments and provided anexplicit physical basis for scales at which process–response systems operate, ranging from weather-relatedevents such as thunderstorms at small scales of space andtime up through tectonic forcing of glacial epochs at largescales. Most of the human-induced changes described inthis volume occur within the second and third classes ofthis model; that is, short period variations and neoglacialevents. The fourth class of orbital forcing, however, is ofimportance to long-term anthropogeomorphic studies,because the transition from late glacial climatic regimeswas a period of great cultural development and prefacedthe massive agricultural developments that sprang fromthe Neolithic. Recognition of multiple drivers andresponses operating at various spatial and temporal scalesis nowwell established, and attempts to work across thosescales should be a goal of future studies.

From a practical perspective, discussions about multi-scalar analysiswere severely limited in 1956bymethods thatcould not adequately characterize the full spectrum of localto macro scales in space, or temporal changes ranging fromhours to millennia. As discussed later, new dating, measure-ment, data storage, data dissemination, and analysistechniques now facilitate analysis at multiple scales.

Not all the theoretical and practical difficulties inseparating processes and responses across scales havebeen resolved (Phillips, 2004). Although the accuracy ofmeasurements has advanced and theory has providedguidance, major obstacles to these analyses remain. Forexample, distinguishing and understanding changesdriven by natural vs. human processes is essential to

understanding the relative role of anthropogenic influ-ence. Unfortunately, isolating human influences onfluvial changes is difficult, because of the absence ofmonitoring in most areas and the difficulty in applyingproxy records over large areas or over relatively shorttime scales at which human-driven change can occur(e.g., Simon and Rinaldi, 2006-this volume). To this day,processes are not monitored in many parts of the world,particularly in remote or developing nations (Marcus etal., 2004; Wohl, 2006-this volume). Difficulties fromnon-uniformities in global data sets are addressed byWalling (2006-this volume) in analyzing suspendedsediment loads at global scales.

Process–response links can also be hard to isolatebecause of factors such as inheritance of form,polygenetic causalities and equifinality, lagged timing,and threshold responses (McDowell et al., 1990).Geomorphic responses to human activities such asforest clearance may, therefore, be quite different in thesame location when considered under different condi-tions or over different time scales. Moreover, recentwork suggests that geomorphic systems are often non-linear (Phillips, 1999). In this case, it may not bepossible to reconstruct which variable drove whichresponse. This situation suggests a need for techniquesto identify non-linearity and scale dependency in riversystems (e.g., Phillips, 2006), so that researchers andmanagers can determine where and over what periodsmonitoring is useful for identifying drivers of changeand predicting future change. Understanding long- toshort-term effects across multiple spatial scales thusremains one of the major challenges to research ofhuman impacts in rivers.

3.2.3. Integrated watershed perspectivesThe post-1950s quantitative revolution in geomor-

phology, coupled with a turn towards using physics tounderstand river process and response, led to the studyof many rivers as objects not tied to the surroundingsystems within the watersheds. This detailed study ofindividual fluvial components in isolation — so im-portant to scientific understanding of causality — canlead to a hydraulic myopia that fails to explain how riversrespond as complex non-linear systems interacting withhuman activities. Contemporary research on humanimpacts in fluvial settings thus often needs to step outsideof this reductionist box and cross over the traditionalboundaries between fluvial geomorphology, aquatic andriparian ecology, river engineering, planning, econom-ics, and related fields. An important development in thisregard is the move towards integrated studies ofwatersheds.


Integrated perspectives have taken hold in keynational and international arenas. In North America,holistic river-management is often referred to as an inte-grated watershed approach where ‘watershed’ is usedsynonymously with catchment or drainage basin (asopposed to its European use as a drainage divide). At thenational level, institutional structures and fundingmechanisms have changed dramatically in response tothe need for integration, and this has created new researchagendas and management policies that emphasizewatershed-scale approaches (USEPA, 1993; Naimanand Bilby, 1998; NRC, 1999; Finlayson and Brizga,2000; Lal, 2000; Downs and Gregory, 2004). The in-ternational support for integrating multiple systems tomanage global fresh water supplies is displayed inAgenda 21 of the United Nations Earth Summit in Rio deJaneiro:

The complex interconnectedness of freshwater sys-tems demands that freshwater management be holistic(taking a catchment management approach) and basedon a balanced consideration of the needs of people andthe environment. The Mar del Plata Action Plan hasalready recognised the intrinsic linkage between waterresource development projects and their significantphysical, chemical, biological, health and socio-economic repercussions (UN, 1992; Section 18.36).

Multi-disciplinary approaches to the study andmanagement of fluvial systems acknowledge the inter-dependencies between channel morphology, aquatic andriparian ecology, climate, water resources, and numerousother systems that govern the magnitude, frequency, andquality of deliveries of water and sediment. Integratedapproaches should also consider changes to upland land-uses that drive the hydrologic and fluvial systems. Animportant value of the Changing the Earth Symposiumwas its broad coverage of many Earth surface systems. Aprimary goal of this Binghamton Symposium is toexamine human impacts on fluvial systems within thisbroad context of catchment dynamics.

Many studies in the 1956 proceedings address basin-scale changes that are relevant to hydrologic and fluvialadjustments, including impacts of fire (Sauer, 1956;Stewart, 1956) and technology (Darby, 1956; Heichel-heim, 1956; Pfeiffer, 1956). Although these changes inland cover clearly effected fluvial systems, rarely werethese changes or watershed processes explicitly linked toriver responses in the papers, or even to the runoff anderosion so critical to rivers. In contrast, Strahler (1956)made thewatershed approach a central theme of his article.In the modern context, it is now ill-advised to considermajor river changes without also considering the basin-

wide context. The 2006 Binghamton Proceedings (thisvolume) merely touches the surface of a vast literature ontopics of watershed changes and the linkages to channelchange. The effects of urbanization on fluvial systems areaddressed by Chin (2006-this volume) and Kang andMarston (2006-this volume). A modern view of historicalchanges and of current erosion conditions in theMediterranean region is provided by Hooke (2006-thisvolume), land cover changes inNorthAmerica are coveredby Knox (2006-this volume) and Poff et al. (2006-thisvolume), and agricultural impacts on South Americanrivers are examined by Harden (2006-this volume).

3.2.4. Global change and climate changeAlthough global climate change has long been an

important theme in studies of anthropogenic change, ithas only emerged recently as a major topic in the contextof human impacts on rivers. The Changing the Earthproceedings clearly indicate the scientific perception ofclimate change in the mid-1950s. The symposiumrevealed a growing awareness of substantial changes intemperature and precipitation regimes and sea levelchanges in the recent past, and some papers discussedimplications of climate change to ecosystems, waterresources, and hydrology. At that time, however, theimportance of global-scale changes in atmosphericchemistry, such as greenhouse gases, was not understood,so the dimension of global anthropogenic climate changewas completely missing. Thus, while Quaternary climatechange was a recurrent theme at the Changing the EarthSymposium, it was viewed as an independent variablehelping to explain human adjustments (Huzayyin, 1956;Sauer, 1956). To the limited degree that human-inducedchanges in climate were considered, they were relegatedto local surface changes to the water budget and resultantradiation balance (Thornthwaite, 1956), and to urbaneffects such as the urban heat island (Landsberg, 1956).Ironically, the realization that human-induced CO2

warming could be significant was first raised in thesame year that the Changing the Earth proceedings werepublished (Plass, 1956) and greatly advanced by one ofthe participants (Landsberg, 1970). Clearly, one of themost fundamental changes over the past fifty years in theunderstanding of human impacts on rivers is therealization that global scale climate changes can bedriven by humans and can be effective agents of changewithinmodern river systems (Goudie, 2006-this volume).

3.3. How research can be conducted

Modern technological innovations have simultaneous-ly complicated and improved the methods by which


human impacts on river systems can be studied. Majorchanges in data collection, analysis, and delivery tech-niques facilitate anthropogeomorphic research into themulti-scalar, integrated watershed perspectives discussedpreviously. These changes include advances in datingtechniques, mapping techniques, digital simulation, andanalytic methods. In addition, advances in the internet—as found throughout the Earth sciences — have greatlyexpanded the ability of researchers and the public toaccess data and research results, to collaborate, and to getinvolved in the development of research agenda, rivermanagement, and policy.

Traditional approaches to collection of field data —ranging from coring to erosion pins — have been en-hanced by numerous new data collection technologiesfor field, laboratory, remote sensing, and analyticalmethods. In the temporal domain, river scholars nowhave access to dating technologies not even imagined inthe 1950s, when dating methods were largely restrictedto relative dating derived from stratigraphy or absolutedates derived from dendrochronology, varves, or long-term written records. Although Libby had begun in thelate 1940s to experiment with radiocarbon as a means ofdating carbon compounds, the reliability of this methodwas still being tested in 1956. Since the 1950s, however,14C and a battery of additional isotopes have becomeextremely important tools for dating late Quaternarystratigraphy, identifying sources of water and sediment,and constraining environmental changes. For example,cosmogenic radionuclides allow dating of erosionalsurfaces and alluvium over Quaternary time periods(36Cl, 26Al, or 10Be) down to a period of months (7Be).Other isotopes such as 210Pb or 137Cs allow fingerprint-ing and dating of sedimentary deposits on intermediatehistorical time scales (Aalto et al., 2003). Additionaldating tools, such as thermoluminescence and opticallystimulated luminescence (OSL), have expanded therange of dates and applications. A broad suite of moderntechniques now enable specification of numerical agesacross a wide range of time scales with quantitativemeasures of uncertainty.

A similar revolution occurred in spatial datacollection and processing techniques. Geographiccoordinates of field locations can now be quicklymeasured to sub-meter resolutions, and mappingsurveys can easily collect large amounts of data andregister them with remote sensing imagery and a varietyof feature attributes. A striking feature of Changing theEarth was the series of oblique aerial photographs ofcultural landscapes in the opening chapter (Gutkind,2006). To contemporary readers, the vantage providedby oblique aerial views was presumably novel and

provided an impressive new synthesis of patterns ofhuman development. In contrast, global and landscapeviews are now commonplace as remote sensing imageryand visualization tools have proliferated, clarifying therelationship between landforms and cultural features.These capabilities are of particular interest in anthropo-genic studies because the scale of human impacts isoften too small to be measurable — if detectable — onstandard topographic maps.

The advent of computer and spatial data in digital formhas powered the development of geographic informationsystems (GIS) and the proliferation of digital elevationmodels (DEMs) and digital maps of soils, vegetation,rivers, roads, as well as other information for much of thedeveloped world. These advances have stimulated thedevelopment of sophisticated spatially distributed numer-ical models and automated simulations of physical sys-tems. Entire research initiatives and companies are nowdevoted to developing algorithms to handle these data setsand digital tools. In rivers, measurements of key hydraulicparameters and habitat characterization can now beacquired with multispectral (Fonstad and Marcus, 2005;Carbonneau et al., in press) and hyperspectral opticalimaging devices (Marcus et al., 2003), ground penetratingradar (Costa et al., 2000), and acoustic doppler currentprofilers (Morlock et al., 2002). Detailed mapping oftopography with radar and lidar (Baltsavias, 1999; Cobbyet al., 2001), and of land cover with a variety of remotesensing devices that operate across the electromagneticspectrum (Jensen, 2000) has become standard. Even ad-vances in microscale to subatomic measurements (Tsong,2006) are gaining attention as geochemical interactionswith geomorphic, hydrologic, and biotic processes areincreasingly incorporated into the studies of humanimpacts on rivers (e.g., Macklin et al., 2006-this volume).

Having praised the capabilities of modern spatialtechnologies, caution should be urged about someconsequences. The power of the resultant spatially dis-tributed models and the persuasive nature of visualiza-tions of the output can lead users to believe that themodelsare real, causing them to bypass the field calibration andvalidation steps that are essential (Wilson and Gallant,2000a). In recent years, a substantial effort has beendevoted to identifying error propagation in models anddigital data sets and how model performances vary indifferent settings (Choudhry et al., 1998; Wilson andGallant, 2000b).

Much information is readily available over the internet,where data repositories, online journals, list servers, andemail have greatly sped up and facilitated access to dataand expertise. Obtaining data, mapping the nature andextent of human and natural features at various scales, and


disseminating the results has never been so easy. Forexample, improvements in the accessibility of globalspatial data recently acceleratedwith the advent ofGoogleEarth™ and other open sources of geographic data. Thesenew techniques hearken a renewed interest in subconti-nental-scale geomorphology that has not been in favorsince the physiographic studies of the early twentiethcentury. New emphases on global change, coupled withthe need for integrated watershed-scale analyses and theavailability of data from other regions, will be likely tostimulate these studies.

3.4. Who does the research — the changing socialcontext

Studies of human impact in fluvial geomorphologyhave evolved greatly over the last fifty years, partly inresponse to changes in the social context of the research.These changes apply to human impact studies and alsomore broadly to Earth sciences. This discussion focuseson institutional changes that have affected how geomor-phology is practiced, primarily in the English speakingworld. The demographic profile of geomorphologistsand the institutional setting of geomorphology outside ofthe English language settings is beyond the scope of thispaper. Interested readers are referred to Walker andGrabau (1993) and Sack (2004) for discussions of thesetopics.

Most investigators of human impacts in 1956 camefrom universities, museums, or government agenciesfocused primarily on monitoring (e.g., the U.S.Geological Survey). These institutions remain crucialto geomorphology as sources of data, funding, expertpersonnel, and other resources. They have been joinedby other groups, however — including additionalgovernment agencies, non-governmental organizations,the private sector, and individuals — who now playmajor roles in driving studies of human impacts onrivers and watersheds. Integrated research approacheshave encouraged many of these new institutional playersand promoted a substantial broadening of the types ofscientists and managers now studying rivers.

Pervasive institutional changes that have arisen fromenvironmental regulations probably are the greatestcauses of change in who is doing human impact studies.TwoActs of the U.S. Congress serve as diverse examplesof environmental legislation that have substantiallychanged how fluvial systems are studied and managedin the United States. The 1969 National EnvironmentalPolicy Act (NEPA, 1969) required all federal agencies toassess the environmental impact of federally fundedprojects. It also introduced to the decision making

process the requirement for public participation inenvironmental planning (James, in press). As a result,studies of human impacts in rivers in the United Statesoften involve research scientists, environmental con-sultants, multiple government agencies, and the public.Despite the diversity of inputs from different sectors,these studies must conform to strictly codified guide-lines, and have generated few new concepts of river formand function. They have created, however, an entireemployment sector for river scientists and, by promotinginterest and employment in human impact analysis, theyhave provided students for universities and generatedfurther research on anthropogenic changes.

The Clean Water Act (CWA) is another example of akey set of environmental laws that has affected the studyand management of human impacts in rivers in the UnitedStates. In the preamble to this lengthy Act, the statedobjectives are “…to restore and maintain the chemical,physical, and biological integrity of the Nation's waters”(CWA, Title I; 33 UCS 1251) (Arbuckle, 1993). Thesegoals have not been met in most water bodies and arearguably unattainable in many, but the laws and regulatoryprocedures that the CWA established are pervasive anddeeply intertwined with environmental management prac-tices. Unfortunately, regulatory efforts have focused largelyon restoring the chemical integrity of water bodies withlittle or no attention to the physical condition (Adler et al.,1993). Fluvial geomorphologists and hydrologists haveplayed an important role, however, in recommendingphysically-based criteria (Marcus, 1989, 1991;Graf, 2001).Furthermore, the CWA has spurred funding initiatives byfederal and state agencies to support basic and appliedresearch in river systems. Similar environmental regulatorystructures and pressures have emerged in many parts of theworld. Collectively, environmental legislation and aware-ness have stimulated interest in geomorphic studies,broadened the cast of participants in fluvial studies, andincreased funding and employment opportunities.

Changes in methodologies have also altered thesocial context of anthropogeomorphic research. Thenew methods usually require more resources in the formof sophisticated laboratory facilities, field equipment,imagery, computer resources, and a host of othersubstantial expenditures. The opportunity for creativeprojects that can be done on low budgets remains for thetruly innovative and resourceful scientist, but, in mostcases, a rod and level survey will no longer suffice. Anincreasing amount of river research is being conductedby teams that include specialists, such as geochemists,hydrologists, pedologists, sedimentologists, surveyors,numerical modelers, and geographic information scien-tists. Furthermore, this list should be broadened for


research teams needed in studies that incorporatecultural and socioeconomic elements.

The need to include the social elements of landscapeprocesses and watershed management in river studies willcall for a greater diversity of participants. Otherwise,geomorphologists in the field risk being viewed asoutsiders without “standing” in the local cultural contextsof the rivers that are to be preserved or enhanced.Researchers should be cognizant of management andrestoration policy and of integrated watershed conditions.Moreover, the modern era of anthropogenic fluvialgeomorphology will likely generate research opportuni-ties at a wide range of scales; from local to global spatialscales and over Quaternary to contemporary time frames.Fragmentation and overspecialization in geomorphictraining should be avoided and greater emphasis placedon broad integrated training.

The explosion of new data sets, new analyticaltechniques, and the greater need for specialists hascreated challenges for non-specialists and those withoutcomputer resources (Marcus et al., 2004). Thus, at atime when the emphasis in environmental science andmanagement is often on increased public involvement,and data delivery makes this involvement increasinglypossible, the disparities between rich and poor, literateand illiterate, digitally and non-digitally proficient, andspecialist and non-specialist have grown. These dispa-rities pose a major obstacle that could undermine manyof the positive advances being made (Clark, 1996;Rango and Shalaby, 1998). How geomorphic research isconducted and explained can determine its relevance orthreaten its effectiveness for one of the major audiencesthat should be reached — those who use and live alongrivers. For this reason, Marcus et al. (2004) argue that itis increasingly important for geomorphologists andhydrologists to plan educational and outreach compo-nents for their research projects, particularly in areaswhere people are less familiar with scientific approachesand rationales.

4. Prospect: A sustainable future and theories ofhuman impacts

The road ahead holds an increasing need for a deeperunderstanding of anthropogenic change in fluvial sys-tems. Rates of fluvial change are accelerating in manyriver basins, public and institutional awareness of thechanges has grown, and the need to manage the changesor adapt to them is growing more acute. Studies of humanimpacts on rivers are rapidly evolving and many changesin research directions may be projected into the future.Rather than trying to catalog these potential incremental

changes, the focus here is on two topics of substantivechange. The first topic, sustainability, reflects a clearmandate from the global community and many nationalgovernments to adjust planning criteria to address longerperiods of resource depletion, human needs, andmaintenance of habitat. The second topic notes the needfor theories that integrate cultural and physical compo-nents of river systems to provide a more holisticunderstanding of the river–human interface.

4.1. Sustainability science

Sustainability refers to the use of resources in waysthat can be maintained over multiple generations whileminimizing damage to environmental and socialsystems. The concept was initially introduced in thesocial sciences, but was later adopted and advanced inthe physical sciences and in river science (Kates et al.,2001; Clark and Dickson, 2003). Adoption of sustain-ability as a policy constraint is generating new researchinitiatives in human impacts and a reconsideration of therole of government in general. The continued expansionof sustainability as a policy guideline will create agrowing demand for geomorphic expertise, because itencourages consideration of long-term environmentalchanges over a period of centuries. This view is inharmony with concepts of geomorphic time andgeomorphic perceptions of landscape change. More-over, sustainability science provides an importantincentive for geomorphologists and social scientists towork together while adopting the integrative, long-termperspectives required by integrated watershed and riverbasin management.

Although the concept of sustainability is invokedrepeatedly in modern environmental research, it is by nomeans a new concept. Indeed, many participants of the1955 Changing the Earth Symposium recognized thepitfalls of equating human domination over nature withprogress (Glacken, 1956) and calls for projecting anenvironmental ethic into the future were lucid (Sears,1956). Carl Sauer clearly expressed the need for anenvironmental ethic of sustainability when he asked:

Are our newly found powers to transform the world,so successful in the short run of the last years, properand wise beyond the tenure of those now living? Towhat end are we committing the world to increasingmomentum of change? (Carl Sauer, 1956; p.66).

Sauer goes on to proclaim:

For the present, living beyond one's means hasbecome civic virtue, increase of ‘output’ the goal of

Fig. 4. Carl O. Sauer at Princeton conference in 1956. Source: WennerGren Foundation. Printed with permission.

Table 1.1Questions revealing the need for anthropogeomorphic theories

Scale:*) Are there spatial or temporal scales at which responses to human

pressures change fundamentally?— If so, at what scales do anthropogenic processes become non-linear,

chaotic, or contingent and do these scales differ from naturalprocesses? The importance of time and space to broad theoreticalrealms implies that fundamental changes to theoretical constructsoccur at different scales of time and space (Fig. 3; Church, 1996).

Hydrologic response:*) Is there a critical proportion of impermeable area of a basin before

human impacts on runoff generation generate downstream changes inchannel morphology (Kang and Marston, 2006-this volume)? If so,why? Do these thresholds change with climate, topography, or soils?

*) Do anthropogenic increases in runoff, due to agricultural or urbanland use, effect extreme flood magnitudes (e.g., ≥50-yearrecurrence intervals), or do natural soils become so saturatedduring those events that human changes are ineffective?

Geomorphic responses:*) Are sediment waves induced by human activities–such as

deforestation, agricultural clearance, or mining–inherentlydifferent in their character and behavior than those generatednaturally by landslides, climate change, or tectonics?

— How does this apply to sediment budgets or to Knox's (1972)biogeomorphic response model?

*) To what extent is channel morphology affected by changes inriparian ecosystems due to vegetation removal or invasion by alienspecies?


society. The prophets of a new world by materialprogress may be stopped by economic limits ofphysical matter… The high moments of history havecome not when man was most concerned with thecomforts and displays of the flesh but when his spiritwas moved to grow in grace. What we need moreperhaps is an ethic and aesthetic under which man,practicing the qualities of prudence and moderation,may indeed pass on to posterity a good Earth (CarlSauer, 1956; p.67).

Sauer (Fig. 4) was a principal in the Changing theEarth leadership.

In the lexicon of modern environmentalism theseconcerns for sustainability could be phrased in terms ofa social responsibility to maintain intergenerationalequity, one of the central tenets of sustainable resourceuse. Although much modern environmental research issteered towards this end, the failure to alter the overallcourse of environmental degradation is striking. A newset of motivating questions and rationales are neededthat cannot come from the engineering and technicalsectors alone, because values are not scientificallytestable. These questions will require collaborationsbetween natural scientists, social scientists, philoso-phers, and ethicists. They will call for new perspectiveson natural process–response systems that includechanges brought about by human agency. Herein lies agrowing challenge to studies of human impacts and tothe next generation of geomorphologists who addressquestions of anthropogenic change.

4.2. Where is theory?

Major progress has been made since 1956 inunderstanding the location, magnitude, and persistenceof human impacts; and these findings have substantiallyadvanced an understanding of the geomorphic humanimprint. On the other hand, as a discipline, little efforthas been made to tie these studies together into broaderoverarching statements about what can be known— andequally important what cannot be known — aboutcause, effect, and prediction in rivers altered by humans.To the degree that theories of river change and stabilityexist, they are largely based on physical studies thatcontrol for, eliminate, or ignore anthropogenic changes,or they may simply treat human influence as anotherphysical or biological process.

To reach the next level of understanding andpredictive capability, theories are needed that specifi-cally apply to anthropogenic change. A number ofquestions can be raised to demonstrate some of the areasof concern (Table 1.1). This list could be extendedindefinitely, but the point is that general principles ofcausality are lacking for this emerging field ofanthropogeomorphology and that conceptual modelsare needed to explain change and provide important


predictive capabilities. The Binghamton 2006 sympo-sium was convened in large part to initiate a dialogueand to spur efforts to identify some incipient theories ofanthropogeomorphology, and to point the way to fruitfulavenues of theoretical development (e.g., Gregory,2006-this volume).

4.2.1. Obstacles to theory developmentThe general lack of theory in anthropogeomorphology

reflects, in part, its early stage of development as a distinctfield of study. Many studies of human impacts on fluvialsystems have been driven by immediate, applied needsand have not focused on identifying theory. Studiesconcerned with aquatic restoration, stream stabilization,or flood hydrology, for example, have been largelyapplied and have not often resulted in the developmentand testing of theories of the human element of systems.

The lack of integrative theory also reflects theemphasis on physical science methods in fluvial geomor-phology and hydrology. Only recently has a substantialeffort been made to integrate studies of the biologicaland physical systems. Integrating cultural phenomenainto a holistic understanding of river response will beeven more difficult. Some barriers arise because scholarsin cultural studies often use language that is alien to Earthscientists, engage in protracted social critiques that arenot perceived to be germane to natural science concerns,and construct qualitative models that can be seeminglyincompatible with quantitative models of natural sys-tems. Individuals who can elucidate both cultures areneeded to bridge these differences. This will requireinstitutional support that enables individuals from onefield to engage in starting up in another. Whether theresource-constrained research community has the will totake such steps is an important question. It is easy to say“interdisciplinary,” but making it happen is anothermatter, particularly when some aspects of disciplines areso different as to seem antithetical. A concerted effort isneeded to overcome differences in methodology, researchgoals, and conceptual frameworks.

Even within geomorphology and hydrology substan-tial cultural barriers exist and the nature of discourse oftenobstructs the development of theory. Some empiricistsargue that established theories are detrimental to theoperation of science because they can bias methods andobservations (Brown, 1996). When studies attempt toextend findings beyond a specific type of impact oroutside of the watersheds for which empirical data areavailable, they often receive harsh criticisms fromreviewers who resist making generalizations aboutsystems where local history and context are important.The difficulties faced by authors in making general-

izations about anthropogenic impact and river responseare real and pervasive. The potential criticism fromreviewers can be swift and hard. Yet, theoretical discourseis essential to science and should be encouraged.

Finally, the complexity of geomorphic systems andtremendous local variability can make it hard to identifyand define causal relationships and generalizablegeomorphic principles, causing scholars to shy awayfrom making overarching statements (Rhoads andThorn, 1996). This becomes even more of a problemwhere nonlinear dynamics introduce chaotic responseand uncertainty in the trajectories of change (Phillips,1996). When human activities are included in geomor-phic systems, the complexity of the system is oftengreatly multiplied. Many researchers, therefore, focuson one human cause of change in one watershed orregion; e.g., post-agricultural dispersion of sedimentsthroughout a basin. Because scholars often lack theresources needed to extend findings further, inquirystops. Clearly, a shift in priorities is needed to expandstudies to the broader range of multiple human changesand interactions between them.

4.2.2. Use of existing physically-based theoriesDespite the obstacles, notable attempts are being

made to progress beyond explanations that apply only tolocal settings. Two avenues have commonly beenfollowed to develop more general theoretical constructs.One approach has been to adopt existing fluvial theoriesto human-impacted systems. Several theories of runoffand sediment generation, fluvial channel processes, andother landform processes are often applied to under-standing human impacts on fluvial systems (e.g.,Schumm, 1977). This has been the dominant approachto understanding human impacts to fluvial systems.Although few existing fluvial and hydrologic theorieswere intended for direct use in studies of human impact,they often may be applied to these changes. Forexample, the variable source area, complex response,and biogeomorphic response models, as well as theconcept of grade and non-linear dynamics are compel-ling theories that may improve interpretations of fluvialresponses to watershed alterations. The question is howto adapt them to incorporate the effects of highlyvariable human activities.

Another approach to developing anthropogenictheory has been to focus on one component of humanimpact and develop theory around that particularfeature, thus allowing characterization of the impact inphysical terms. For example, Graf (2006-this volume)provides a general model for the nature and range ofdam impacts by examining stream segments above and


below dams in relatively undisturbed settings. In thisway, a general theory of dam impacts is developedbecause the human component can be treated as achange in flow regime.

The direct transfer of physical models to broaderconceptualizations of human impact theory is oftenjustifiable, especially where human impacts can becharacterized in physical terms. In many settings,however, the human presence is so intertwined in thehistory and in the landscape, that separation of humanimpacts from natural changes is impossible. Much ofGraf's effort in the example above went toward locatingrelatively undisturbed river reaches above major dams.Moreover, human activitiesmay result in system responsethat cannot be subsumed by conventional fluvial theorybased on physical science (Urban, 2002; Gregory, 2006-this volume). Research is needed on the extent to whichexisting theories may be applicable to situations wherehuman impacts are a central factor. This need calls for anexamination of elements of anthropogenic fluvial changethat are unique and defy categorization by traditionalphysics, chemistry, or biological parameters.

4.2.3. Anthropogeomorphic theoryFor theories of anthropogeomorphology to advance, a

change in attitude within geomorphology and hydrologymay be needed about the use of terms such as scientific“theories” and “laws.” These terms are often held up asparagons of scientific accomplishment, that can only beclaimed when the universality of application can match thelegendary status of theories by Newton, Einstein, or Bohr.Lofty notions of what theory generation should be mayinhibit a scholar's willingness to make generalizations.Whereas such strict and high standards may prevent thetrivial from being elevated to the status of the grand, theyalso promote the promulgation of studies confined toempirical findings and local case studies loaded withidiosyncrasies. Empirical articles making local claims ofexplanation are far more likely to be published, so thetendency for empiricism is reinforced. In some ways, thiscan be a good thing, as it encourages research to producedata that can be used to test and develop theories. Inactuality, however, few theories have been forthcomingfrom the data, and greater efforts are needed to extractgeneral principles from applied case studies.

Cultural phenomena need to be explicity addressed bytheory. Spatial and historical variations in livelihoodstrategies, local culture, and politics may tell us moreabout contemporary floodplain form (e.g., Bravard,2006), than a model that is based on flood recurrenceintervals. The potential for development of theories offluvial anthropogeomorphology, however, is problematic;

it is more easily stated than practiced. The development ofsuch theories should be given a high priority for futurework because anticipating future human impacts requiresknowledge of how humans interact with natural systems.One obvious statement that can be made in this regard isthat geomorphologists should seek collaborations withsocial scientists, planners, humanist scholars, localresidents, and policy makers to establish a broaderunderstanding of the role of humans in these systems.Collaboration alone, however, is not enough. All playersmust move outside their intellectual comfort zones andwillingly adapt their methods, research designs, andvocabulary to accommodate diverse perspectives on whatconstitutes valid knowledge, understanding, and predic-tion. If only physically-based findings are produced, onlyphysically-based predictability will be achieved. Anthro-pogeomorphology calls for newmethods of discourse thattruly allow culture and nature to be included in theories ofhuman impacts and environmental change in riversystems. Thomas (1956b, p. xxxvii) clearly understoodthis when he stated:

“The dichotomy of man and nature is thus seen as anintellectual device and as such should not beconfused with reality; no longer can man's physi-cal–biological environment be treated, except intheory, as ‘natural’.”

5. Summary

Studies of the impact of humans on rivers haveprogressed far since the 1956 Man's Role proceedings.The works of pioneers such as Luna Leopold (e.g., 1953,1956) and Arthur Strahler (e.g., 1952, 1956) were justbeginning to guide the growth of a new quantitative,process-oriented approach to river studies. The contrastbetween research in 1956 and 2006 is thus remarkable inmany ways. Human impact studies are now driven to amuch greater extent by environmental regulations,institutional needs, and restoration goals, which in turnhave led to increased involvement of governmentregulators, nongovernmental organizations, and consul-tants in river studies. Methods now include a remarkablearray of dating techniques, spatial data acquisition at localto global scales, and computer-based quantitative analy-sis, mapping andmodeling. The evolving social drivers ofresearch and new methods have led to shifts in topics thatare studied, with increasing emphasis on channel changes,human agency acrossmultiple scales, and development ofapproaches to sustainability and integrated managementthroughout watersheds. Paradigms used to characterizeriver responses to the impacts of humans are often


different, commonly including concepts of nonlinearity,complexity, and thresholds.

Yet at another level, much about human impactresearch in rivers remains the same. The 1956 Changingthe Earth proceedings highlighted the need to look at thebig picture –to assess human impacts at landscape scalesand over century-to-millennial time periods so as to graspthe true scope of human influences on Earth. Inarticulating this need, the scholars of 1956 made it clearthat landscapes are contingent; that they evolve differentlyunder different natural and cultural influences. Thesethemes are echoed in the watershed perspectives, thecomplex response paradigms, and the historical recon-structions conducted by modern-day river scientists andreflected by articles in this volume. Similarly, the scholarsof the Changing the Earth Symposium clearly articulatedthe need for models that bridge the cultural studies–physical science divide. River scholars continue tograpple with this issue, suggesting it may be time toadopt Rhoad's (2004, p. 752) recommendation “…toforget about conceptualizing how an integrative geogra-phy should work and get on with the business of trying tomake it work.”

A common sense of purpose also permeates theliterature of 1956 and 2006, although that purpose isoften muted in the dry prose of modern scientific writing.Whether it be through explanation of human impacts,calls for new regulatory measures, discussions of newresearch approaches, or arguments for greater involve-ment of river scientists in decision making, a clear anddeep sense of caring for rivers pervades the articles in thisvolume and the larger literature on human impacts inrivers. Thus, while many of the particulars of scholarshipon human impacts in rivers have changed, the underlyingintent remains the same: to enrich our understanding ofhow humans alter rivers, and to protect and enhance therivers that we study.

References

Aalto, R., Maurice-Bourgoin, L., Dunne, T., Montgomery, D.R.,Nittrouer, C.A., Guyot, J.L., 2003. Episodic sediment accumula-tion on Amazonian flood plains influenced by El Nino/SouthernOscillation. Nature 425 (6957), 493–497.

Adler, R.W., Landman, J.C., Cameron, D.M., 1993. The Clean WaterAct 20 Years Later. Natural Resources Defense Council. IslandPress, Wash., D.C. 320 pp.

Arbuckle, J.G., 1993.Water pollution control. Ch. 6, In: Arbuckle, J.G.,et al. (Ed.), Environmental LawHandbook, 12th ed. Govt. InstitutesInc., Rockland, MD. 550 pp.

Audubon, J.J., 1831–1839. Ornithological Biography, or an Account ofthe Habits of the Birds of the United States of America. AdamBlack,Edinburgh. Vol. I (1831), Vol. II (1835), Vol. III (1835), Vol. IV(1838), Vol. V (1839). Reprinted in 1979 by Volair Books. NY.

Baltsavias, E.P., 1999. A comparison between photogrammetry andlaser scanning. Photogrammetry and Remote Sensing 54, 83–94.

Beyer, P.J., 2005. Dams in Geomorphology. Proceedings 33rdBinghamton Symp. in Geomorphology. Oct. 12–13, 2002. Else-vier, The Netherlands. 268 pp.

Bravard, J.P., 2006. Bridging physical and human dimensions ofgeography through geo-historical approaches: some examplesfrom France. Talk Delivered in the AAG's Presidential PlenarySession, Geography: the Original Integrated EnvironmentalScience, May 8, 2006, The 2006 Annual Meetings of theAssociation of American Geographers, Chicago, IL.

Brooks, A.P., Howell, T., Abbe, T.B., Arthington, A.H., 2006.Confronting hysteresis: wood based river rehabilitation in highlyaltered riverine landscapes of south-eastern Australia. In: James, L.A., Marcus, W.A. (Eds.), The Human Role in Changing FluvialSystems. Proc. 37th Internat. Binghamton Geomorphology Symp.Geomorphology, 79, pp. 395–422 (this volume). doi:10.1016/j.geomorph.2006.06.035.

Brown, H.I., 1996. The methodological roles of theory in science. In:Rhoads, B.L., Thorn, C.E. (Eds.), The Scientific Nature ofGeomorphology. Proc. 27th Binghamton Symp., Sept. 1996. J.Wiley & Sons, N.Y, pp. 3–20.

Butler, D., 2006. Human-induced changes in animal populations anddistributions, and their subsequent effects on fluvial systems. In:James, L.A., Marcus, W.A. (Eds.), The Human Role in ChangingFluvial Systems. Proc. 37th Internat. Binghamton GeomorphologySymp. Geomorphology, 79, pp. 448–459 (this volume).doi:10.1016/j.geomorph.2006.06.026.

Carbonnneau, P.E., Lane, S.N., Bergeron, N., in press. Feature basedimage processing methods applied to bathymetric measurementsfrom airborne remote sensing in fluvial environments. EarthSurface Processes and Landforms. doi:10.1002/esp.1341.

Carson, R., 1962. Silent Spring. Houghton Mifflin, Boston.Chin, A., 2006. Urban transformation of river landscapes in a global

context. In: James, L.A., Marcus, W.A. (Eds.), The Human Role inChanging Fluvial Systems. Proc. 37th Internat. BinghamtonGeomorphology Symp. Geomorphology, 79, pp. 460–487 (thisvolume). doi:10.1016/j.geomorph.2006.06.033.

Choudhry, S.,Morad,M.,Miller, D.J., Sias, J., 1998.GIS errors and surfacehydrologic modeling: an examination of effects and solutions. Journalof Surveying Engineering-ASCE 124 (3), 134–143.

Church, M., 1996. Space, time and the mountain – how do we orderwhat we see? In: Rhoads, B.L., Thorn, C.E. (Eds.), The ScientificNature of Geomorphology. Proceedings 27th Binghamton Symp.,Sept. 27–29, 1996. J. Wiley & Sons Ltd, N.Y., pp. 147–170.

Clark, M.J., 1996. Professional integrity and the social role of hydro-GIS. In: Kovar, K. (Ed.), Application of Geographic InformationSystems in Hydrology and Water Resources Management. Proc.HydroGIS'96 conference, Vienna, 1996, vol. 235. IAHS, Pub.,pp. 279–287.

Clark, W.C., Dickson, N.M., 2003. Sustainability science: theemerging research program. Proceedings of the National Academyof Sciences 100 (14), 8059–8061.

Cobby, D.M., Mason, D.C., Davenport, I.J., 2001. Image proces-sing of airborne scanning laser altimetry data for improved riverflood modelling. Photogrammetry and Remote Sensing 56,121–138.

Cooke, R.U., Reeves, R.W., 1976. Arroyos and EnvironmentalChange in the American South-West: Oxford, Clarendon Press.213 pp.

Cooper, S. F. [published as “A Lady”], 1850. Rural Hours. George P.Putnam, New York.





http://dx.doi.org/10.1002/esp.134


Costa, J.E., Spicer, K.R., Cheng, R.T., Haeni, F.P., Melcher, N.B.,Thurman, E.M., 2000. Measuring stream discharge by non-contactmethods: a proof of concept experiment. Geophysical ResearchLetters 27 (4), 553–556.

Crutzen, P.J., 2002. Geology of mankind. Nature 415, 23.Crutzen, P.J., Stoermer, E.F., 2000. The “Anthropocene.” Global

Change Newsletter 41, 17–18. International Geosphere–BiosphereProgramme (IGBP).

Darby, H.C., 1956. The clearing of the woodland in Europe. In:Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 183–216.

Davis, J.H., 1956. Influences of man upon coast lines. In: Thomas Jr.,W.L. (Ed.), Man's Role in Changing the Face of the Earth. Univ.Chicago Press, Chicago, pp. 504–521.

De Chardin, P.T., 1956. The antiquity and world expansion of humanculture. In: Thomas Jr., W.L. (Ed.), Man's Role in Changing theFace of the Earth. Univ. Chicago Press, Chicago, pp. 103–112.

Downs, P.W., Gregory, K.J., 2004.River ChannelManagement: TowardsSustainable Catchment Hydrosystems. Arnold, London. 395 pp.

Fejos, P., 1956. Foreword. In: Thomas Jr., W.L. (Ed.), Man's Rolein Changing the Face of the Earth. Univ. Chicago Press, Chicago,pp. vii–viii.

Finlayson, B.L., Brizga, S.O., 2000. Introduction. River Management:the Australian Experience. J.Wiley& Sons, N.Y., pp. 1–10. 301 pp.

Fonstad, M., Marcus, W.A., 2005. Remote sensing of stream depthswith a hydraulically-assisted bathymetry (HAB) model. Geomor-phology 72 (1–4), 107–120.

Fox, S., 1985. The American Conservation Movement: John Muir andHis Legacy. Univ. Wisconsin Press, Madison, WI. 436 pp.

Glacken, C.J., 1956. Changing ideas of the habitable world. In:Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 70–92.

Glacken, C.J., 1967. Traces on the Rhodian Shore: Nature and Culturein Western Thought from Ancient Times to the End of theEighteenth Century. Univ. Calif. Press, Berkeley. 763 pp.

Goudie, A., 1995. The Changing Earth: Rates of GeomorphologicalProcesses. Blackwell, Oxford, UK. 352 pp.

Goudie, A., 2000. The Human Impact on the Natural Environment, 5thed. MIT Press, Cambridge, MA. 511 pp.

Goudie, A.S., 2006. Global warming and fluvial geomorphology. In:James, L.A., Marcus, W.A. (Eds.), The Human Role in ChangingFluvial Systems. Proc. 37th Internat. Binghamton GeomorphologySymp. Geomorphology, 79, pp. 384–394 (this volume).doi:10.1016/j.geomorph.2006.06.023.

Graf, W.L., 1996. Geomorphology and policy for restoration ofimpounded American rivers: what is “natural?”. In: Rhoads, B.L.,Thorn, C.E. (Eds.), The Scientific Nature of Geomorphology.Proceedings 27th Binghamton Symp., Sept. 27–29, 1996, J. Wiley& Sons Ltd, N.Y., pp. 443–473. 481 pp.

Graf, W.L., 2001. Damage control: restoring the physical integrity ofAmerica's rivers. Annals of the Association of AmericanGeographers 91 (1), 1–27.

Graf, W.L., 2006. Downstream hydrologic and geomorphic effects oflarge dams on American rivers. In: James, L.A., Marcus, W.A.(Eds.), The Human Role in Changing Fluvial Systems. Proc. 37thInternat. Binghamton Geomorphology Symp. Geomorphology, 79,pp. 336–360 (this volume). doi:10.1016/j.geomorph.2006.06.022.

Gregory, K.J., 2006. The human role in changing river channels. In:James, L.A., Marcus, W.A. (Eds.), The Human Role in ChangingFluvial Systems. Proc. 37th Internat. Binghamton GeomorphologySymp. Geomorphology, 79, pp. 172–191 (this volume).doi:10.1016/j.geomorph.2006.06.018.

Gutkind, E.A., 2006. Our world from the air: conflict and adaptation.In: Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 1–44.

Haff, P.K., 2001. Neogeomorphology, prediction, and the anthropiclandscape. In: Wilcock, P.R., Iverson, R.M. (Eds.), Prediction inGeomorphology, AGU Geophysical Monograph Series, vol. 135.doi:10.1029/135GM02.

Hammond, S.H., 1857. Wild Northern Scenes; or, Sporting Adven-tures with the Rifle and the Rod. Derby & Jackson, New York.

Happ, S.C., 1944. Sedimentation in South Carolina piedmont valleys.American Journal of Science 243, 113–126.

Harden, C.P., 2006. Human impacts on headwater fluvial systems inthe northern and central Andes. In: James, L.A., Marcus, W.A.(Eds.), The Human Role in Changing Fluvial Systems. Proc. 37thInternat. Binghamton Geomorphology Symp. Geomorphology, 79,pp. 249–263 (this volume). doi:10.1016/j.geomorph.2006.06.021.

Hays, S.P., 1959. Conservation and the Gospel of Efficiency; theProgressive Conservation Movement, 1890–1920. Harvard Univ.Press, Cambridge, MA.

Heichelheim, F.M., 1956. Effects of classical antiquity on the land. In:Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 165–182.

Hooke, J.M., 2006. Human impacts on fluvial systems in theMediterranean Region. In: James, L.A., Marcus, W.A. (Eds.),The Human Role in Changing Fluvial Systems. Proc. 37th Internat.Binghamton Geomorphology Symp. Geomorphology, 79, pp.311–335 (this volume). doi:10.1016/j.geomorph.2006.06.036.

Hupp, C.R., Osterkamp, W.R., Howard, A.D. (Eds.), 1995. Biogeo-morphology, Terrestrial and Freshwater Systems. Proceedings 26thBinghamton Symposium in Geomorphology, Oct. 6–8, 1995.Elsevier, Amsterdam. 347 pp.

Huzayyin, S., 1956. Changes in climate, vegetation, and humanadjustments in the Saharo-Arabian belt with special references toAfrica. In: Thomas Jr., W.L. (Ed.), Man's Role in Changing theFace of the Earth. Univ. Chicago Press, Chicago, pp. 304–323.

James, L.A., in press. Water and Watersheds. Prentice Hall, UpperSaddle River, NJ.

Jensen, J.R., 2000. Remote Sensing of the Environment: an EarthResources Perspective. Prentice Hall, Upper Saddle River. 544 pp.

Kang, R.S., Marston, R.A., 2006. Geomorphic effects of rural-to-urban land use conversion on three streams in the central RedbedPlains of Oklahoma. In: James, L.A., Marcus, W.A. (Eds.), TheHuman Role in Changing Fluvial Systems. Proc. 37th Internat.Binghamton Geomorphology Symp. Geomorphology, 79, pp.488–506 (this volume). doi:10.1016/j.geomorph.2006.06.034.

Kates, R.W., Turner, B.L., Clark,W.C., 1990. The great transformation. In:Turner, B.L., Clark, W.C., Kates, R.W., Richards, J.F., Mathews, J.T.,Meyer, W.B. (Eds.), The Earth as Transformed by Human Action:Global and Regional Changes in the Biosphere over the Past300 Years. Cambridge Univ. Press, Cambridge, UK, pp. 1–17. 713 pp.

Kates, R.W., Clark, W.C., Corell, R., Hall, J.M., Jaeger, C.C., Lowe, I.,McCarthy, J.J., Schellnhuber, H.J., Bolin, B., Dickson, N.M.,Faucheux, S., Gallopin, G.C., Grübler, A., Huntley, B., Jäger, J.,Jodha, N.S., Kasperson, R.E., Mabogunje, A., Matson, P.,Mooney, H., Moore III, B., O'Riordan, T., Svedin, U., 2001.Environment and development: sustainability science. Science292, 641–642.

Kiersch, G.A., 1998. Engineering geosciences and military operations.Engineering Geology 49, 123–176.

Klimm, L.E., 1956. Man's ports and channels. In: Thomas Jr., W.L.(Ed.), Man's Role in Changing the Face of the Earth. Univ.Chicago Press, Chicago pp. 522–541.




http://dx.doi.org/10.1029/135GM02





Knox, J.C., 1972. Valley alluviation in Southwestern Wisconsin.Annals of the Association of American Geographers 62, 401–410.

Knox, J.C., 2006. Floodplain sedimentation in the upper MississippiValley: natural versus human accelerated. In: James, L.A., Marcus,W.A. (Eds.), The Human Role in Changing Fluvial Systems. Proc.37th Internat. Binghamton Geomorphology Symp. Geomorphol-ogy, 79, pp. 286–310 (this volume). doi:10.1016/j.geomorph.2006.06.031.

Lal, R., 2000. Rationale for watershed as a basis for sustainablemanagement of soil and water resources. In: Lal, R. (Ed.),Integrated Watershed Management in the Global Ecosystem. CRCPress, N.Y, pp. 3–16. 395 pp.

Landsberg, H.E., 1956. The climate of towns. In: Thomas Jr., W.L.(Ed.), Man's Role in Changing the Face of the Earth. Univ.Chicago Press, Chicago, pp. 584–606.

Landsberg, H.E., 1970. Man-made climatic changes. Science 170,1265–1268.

Leopold, L.B., 1953. Downstream change of velocity in rivers.American Journal of Science 251, 606–624.

Leopold, L.B., 1956. Land use and sediment yield. In: Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of the Earth. Univ.Chicago Press, Chicago, pp. 639–647.

Lowenthal, D., 1965. Introduction. In: Lowenthal, D. (Ed.), The JohnHarvard Library, Man and Nature, by George Perkins Marsh.Harvard Univ. Press, Cambridge, MA, pp. ix–xxiv.

Lowenthal, D., 1990. Awareness of human impacts: changing attitudesand emphases. In: Turner, B.L., Clark, W.C., Kates, R.W.,Richards, J.F., Mathews, J.T., Meyer, W.B. (Eds.), The Earth asTransformed by Human Action: Global and Regional Changes inthe Biosphere over the Past 300 Years. Cambridge Univ. Press,Cambridge, UK, pp. 121–135.

Macklin, M., Brewer, P.A., Hudson-Edwards, K.A., Coulthard, T.J.,Dennis, I.A., Lechler, P.J., Miller, J.R., Turner, J.N., 2006. Ageomorphological–geochemical approach to river basin manage-ment in mining-affected rivers. In: James, L.A., Marcus, W.A.(Eds.), The Human Role in Changing Fluvial Systems. Proc. 37thInternat. Binghamton Geomorphology Symp. Geomorphology, 79,pp. 423–447 (this volume). doi:10.1016/j.geomorph.2006.06.024.

Malanson, G., 1993. Riparian Landscapes. Cambridge UniversityPress, Cambridge, MA.

Marcus, W.A., 1989. Regulating contaminated sediments in aquaticenvironments: a hydrologic perspective. Environmental Manage-ment 13 (6), 703–713.

Marcus, W.A., 1991. Managing contaminated sediments in aquaticenvironments: identification, regulation and mitigation. Environ-mental Law Reporter 21 (1), 10020–10032.

Marcus, W.A., Legleiter, C.J., Aspinall, R.J., Boardman, J.W.,Crabtree, R., 2003. High spatial resolution, hyperspectral(HSRH) mapping of in-stream habitats, depths, and woody debrismountain streams. Geomorphology 55 (1–4), 363–380.

Marcus, W.A., Aspinall, R.J., Marston, R.A., 2004. GIS and surfacehydrology. In: Schroder Jr., J.F., Bishop, M.P. (Eds.), GeographicInformation Science and Mountain Geomorphology. PraxisScientific Publishing, Chichester, UK, pp. 343–379.

Marsh, G.P., 1864. Man and nature: physical geography as modifiedby human action. In: Lowenthal, D. (Ed.), N.Y.: Charles Scribner.Reissued with Annotations, 1965. Harvard Univ. Press, Cam-bridge, MA.

McDowell, P.F., Webb III, T., Bartlein, P.J., 1990. Long-termenvironmental change. In: Turner, B.L., Clark, W.C., Kates, R.W.,Richards, J.F., Mathews, J.T., Meyer, W.B. (Eds.), The Earth asTransformed by Human Action: Global and Regional Changes in the

Biosphere over the Past 300 Years. Cambridge Univ. Press,Cambridge, UK, pp. 143–162.

Morlock, S.E., Nguyen, H.T., Ross, J.H., 2002. Feasibility ofacoustic doppler velocity meters for the production of dischargerecords from U.S. Geological Survey streamflow-gaging sta-tions. U.S. Geol. Survey Water-Resources Investigations Report01–4157.

Mumford, L., 1931. The Brown Decades: a Study of the Arts inAmerica, 1865–1895. Harcourt Brace & Co, New York.

Naiman, R.J., Bilby, R.E., 1998. River ecology and management in thePacific coastal ecoregion. River Ecology and Management: Lessonsfrom the Pacific Coastal Ecoregion. Springer-Verlag, N.Y, pp. 1–10.705 pp.

National Environmental Policy Act (NEPA), 1969. Public Law 91-190, 42 USC 4321–4347.

National Research Council (NRC), 1992. Restoration of aquaticecosystems. Committee on Restoration of Aquatic Ecosystems.Nat. Academy Press, Wash., D.C. 552 pp.

National Research Council (NRC), 1999. New Strategies forAmerica's Watersheds. Nat. Academy Press, Wash., D.C. 311 pp.

Neal, J.T., 1998. Swords into plowshares, military geology and nationalsecurity projects. In: Underwood, J.R., Guth, P.L. (Eds.), MilitaryGeology in War and Peace, Reviews in Engineering Geology,Geological Soc. America, Boulder, CO, vol. XIII, pp. 111–116.Chap. 10.

Pfeiffer, G., 1956. The quality of peasant living in central Europe. In:Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 240–277.

Phillips, J.D., 1996. Deterministic complexity, explanation, andpredictability in geomorphic systems. In: Rhoads, B.L., Thorn,C.E. (Eds.), The Scientific Nature of Geomorphology. Proc.27th Binghamton Symp., Sept. 1996. J. Wiley & Sons, N.Y.,pp. 315–335.

Phillips, J.D., 1999. Divergence, convergence, and self-organization inlandscapes. Annals of the Association of American Geographers89 (3), 466–488.

Phillips, J.D., 2006. Deterministic chaos and historical geomorphology: areview and look forward. Geomorphology 76 (1–2), 109–121.

Phillips, Jonathan D., 2004. Independence, contingency, and scalelinkage in physical geography. In: Sheppard, E., McMaster, R.B.(Eds.), Scale and Geographic Inquiry: Nature, Society, and Method.Blackwell, pp. 86–100.

Pisani, D.J., 1996.Water, Land, and Law in theWest: the Limits of PublicPolicy, 1850–1920. Univ. Kansas Press, Lawrence, KS. 273 pp.

Plass, G.N., 1956. Effect of carbon dioxide variations on climate.American Journal of Physics 24 (5), 376–387.

Poff, N.L., Bledsoe, B.P., Cuhaciyan, C.O., 2006. Hydrologicalterations due to differential land use across the contiguousUnited States: geomorphic and ecological consequences for streamecosystems. In: James, L.A., Marcus, W.A. (Eds.), The HumanRole in Changing Fluvial Systems. Proc. 37th Internat. Bingham-ton Geomorphology Symp. Geomorphology, 79, pp. 264–285 (thisvolume). doi:10.1016/j.geomorph.2006.06.032.

Rango, A., Shalaby, A.I., 1998. Operational applications of remotesensing in hydrology: success, prospects and problems. Hydro-logical Sciences Journal 43 (6), 947–968.

Rhoads, B.L., 2004. Whither physical geography? Annals of theAssociation of American Geographers 94 (4), 748–755.

Rhoads, B.L., Thorn, C.E., 1996. Toward a philosphophy ofgeomorphology. The Scientific Nature of Geomorphology. In:Rhoads, B.L., Thorn, C.E. (Eds.), Proc. 27th Binghamton Symp.,Sept. 1996. J. Wiley & Sons, N.Y., pp. 115–143.






Rosgen, D., 1996. Applied River Morphology. Wildland Hydrology,Pagosa Springs, CO.

Russell, R.J., 1956. Environmental changes through forces indepen-dent of man. In: Thomas Jr., W.L. (Ed.), Man's Role inChanging the Face of the Earth. Univ. Chicago Press, Chicago,pp. 453–470.

Sack, D., 2004. Experiences and viewpoints of selected womengeomorphologists for the mid-20th century. Physical Geography 25,438–452.

Sauer, C.O., 1956. The agency of man on earth. In: Thomas Jr., W.L. (Ed.),Man's Role in Changing the Face of the Earth. Univ. Chicago Press,Chicago, pp. 49–69.

Schumm, S.A., 1977. The Fluvial System. J. Wiley & Sons. 338 pp.Schumm, S.A., Lichty, R.W., 1965. Time, space and causality in

geomorphology. American Journal of Science 263, 110–119.Sears, P.B., 1956. The processes of environmental change by man. In:

Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 471–484.

Shaler, N.S., 1905. Man and the Earth. Duffield & Co, New York.240 pp.

Simon, A., Rinaldi, M., 2006. Channelized and other incised streams:experiences with excess flow energy and stream power incompressed time scales. In: James, L.A., Marcus, W.A. (Eds.),The Human Role in Changing Fluvial Systems. Proc. 37th Internat.Binghamton Geomorphology Symp. Geomorphology, 79, pp.361–383 (this volume). doi:10.1016/j.geomorph.2006.06.037.

Stewart, O.C., 1956. Fire as the first great force employed by man. In:Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 115–133. 448 pp.

Strahler, A.N., 1952. Dynamic basis of geomorphology. Bulletin of theGeological Society of America 63, 923–938.

Strahler, A.N., 1956. The nature of induced erosion and aggradation.In: Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 621–638.

Thomas Jr., W.L. (Ed.), 1956a. Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago. 1193 pp.

Thomas Jr., W.L., 1956b. Introductory. In: Thomas Jr., W.L. (Ed.),Man's Role in Changing the Face of the Earth. Univ. ChicagoPress, Chicago, pp. xxi–xxxviii.

Thomas, H.E., 1956c. Changes in quantities and qualities of groundand surface water. In: Thomas Jr., W.L. (Ed.), Man's Role inChanging the Face of the Earth. Univ. Chicago Press, Chicago,pp. 542–563.

Thoreau, H.D., 1854. Walden; or, Life in the Woods. In: Sayre, R.F.(Ed.), Ticknor and Fields, Boston.

Thornthwaite, C.W., 1956. Modification of rural microclimates. In:Thomas Jr., W.L. (Ed.), Man's Role in Changing the Face of theEarth. Univ. Chicago Press, Chicago, pp. 567–583.

Tsong, T.T., 2006. Fifty years of seeing atoms. Physics Today 59 (3),31–37.

Turner II, B.L., Clark, W.C., Kates, R.W., Richards, J.F., Mathews, J.T.,Meyer, W.B. (Eds.), 1990. The Earth as Transformed by HumanAction: Global and Regional Changes in the Biosphere over the Past300 Years. Cambridge Univ. Press, Cambridge. 713 pp.

United Nations. 1992. Protection of the quality and supply offreshwater resources: application of integrated approaches to thedevelopment, management and use of water resources. The RioDeclaration on Environment and Development. Agenda 21 of theUnited Nations Programme of Action. Ch. 18. Section 2. U.N. Pub.No. E.93.I.11. U.N. Dept. Public Information.

Urban, M., 2002. Conceptualizing anthropogenic change in fluvialsystems. Professional Geographer 54 (2), 204–217.

U.S. Environmental Protection Agency, 1993. The watershedprotection approach. Annual Report, 1992. Office of Water. EPA840-S-93-001. U.S. Govt. Printing Office, Wash., D.C. 64 pp.

Vitek, J.D., Ritter, D.F., 1993. Geomorphology in the USA. In: Walker,H.J., Grabau, W.E. (Eds.), The evolution of geomorphology: anation-by-nation summary of development. J. Wiley & Sons, N.Y.,pp. 469–481. 539 pp.

Waling, D., 2006. Human impact on land–ocean sediment transfer bythe world’s rivers. In: James, L.A., Marcus, W.A. (Eds.), TheHuman Role in Changing Fluvial Systems. Proc. 37th Internat.Binghamton Geomorphology Symp. Geomorphology, 79, pp.192–216 (this volume). doi:10.1016/j.geomorph.2006.06.019.

Walker, H.J., Grabau, W.E., 1993. The Evolution of Geomorphology: aNation-by-nation Summary of Development. J. Wiley & Sons, N.Y.539 pp.

Wilson, R.M., 2005. Retrospective review: man's role in changing theface of the earth. Environmental History 10 (4), 564–566.

Wilson, J.P., Gallant, J.C., 2000a. Digital terrain analysis. In: Wilson, J.P.,Gallant, J.C. (Eds.), Terrain Analysis: Principles and Applications.John Wiley & Sons, Hoboken, New Jersey, pp. 1–28.

Wilson, J.P., Gallant, J.C. (Eds.), 2000b. Terrain Analysis: Principles andApplications. John Wiley & Sons, Hoboken, New Jersey. 479 pp.

Wittfogel, K.A., 1956. The hydraulic civilizations. In: Thomas Jr.,W.L. (Ed.), Man's Role in Changing the Face of the Earth. Univ.Chicago Press, Chicago, pp. 152–164.

Woeikof, A.I., 1901. De l'influence de l'homme sur la terre. Annalesde Géographie 10, 97-114, 193–215.

Wohl, E., 2006. Human impacts to mountain streams. In: James, L.A.,Marcus, W.A. (Eds.), The Human Role in Changing FluvialSystems. Proc. 37th Internat. Binghamton Geomorphology Symp.Geomorphology, 79, pp. 217–248 (this volume). doi:10.1016/j.geomorph.2006.06.020.

Wolman, A., 1956. Disposal of man's waste. In: Thomas Jr., W. (Ed.),Man's Role in Changing the Face of the Earth. Univ. ChicagoPress, Chicago, pp. 807–816.





The human role in changing fluvial systems: Retrospect, inventory … · The human role in changing...

Documents

Transcript of The human role in changing fluvial systems: Retrospect, inventory … · The human role in changing...